Correlation between fractional exhaled nitric oxide and Asthma Control Test score and spirometry parameters in on-treatment- asthmatics in Ho Chi Minh City

Journal of Thoracic Disease, vol. 12, pp. 2197–2209

Abstract

BACKGROUND: Although fractional exhaled nitric oxide (FeNO) is a reliable and easily applied marker of airway inflammation in asthma, the relationship between FeNO and indicators of asthma control [Asthma Control Test (ACT) score] and/or severity (spirometry parameters) remains unclear. This study aims to determine possible correlations between FeNO and ACT score; and between FeNO and spirometry parameters. METHODS: A cross-sectional study with convenience sampling was conducted among ambulatory patients in the Asthma & COPD clinic at the University Medical Center, Ho Chi Minh City from March 2016 to March 2017. Using measurement of FeNO, the ACT questionnaire and a spirometry test, correlations were determined between FeNO and the ACT score and spirometry parameters. RESULTS: Four hundred and ten asthmatic patients (mean age 42 years; 65% female) were included and analyzed; their mean time since onset of asthma was 9.5 years. All patients were treated following step 2 to 4 of GINA guidelines. Mean (SD) FeNO was 29.5 (24.4) parts per billion (ppb) and mean (SD) ACT score was 20.5 (40). A significant difference in FeNO values was found among the three groups with different asthma control levels categorized according to the ACT score (P=0.001) but was not found among the three groups with different asthma treatment levels (P=0.425). FeNO was significantly inversely correlated with the ACT score (Spearman's r =-0.224, P<0.001) and with spirometry parameters indicate airway obstruction such as predicted FEV1, FEV1/FVC, predicted PEF and predicted FEF25-75% with Spearman's r were -0.187; -0.143; -0.091 and -0.195, respectively (all P<0.05), whereas no correlation between FeNO and FVC-an indicator of airway restriction-was found. CONCLUSIONS: In these asthmatic patients in Vietnam, an inverse correlation was found between FeNO and the ACT score and between FeNO and spirometry indicators of airway obstruction. Therefore, FeNO may be a useful tool in asthma management.

Authors 2

1. Vinh Nguyen‐Nhu Aachen Department of Public Health and Primary Care

   Leiden University Medical Center · University of Medicine and Pharmacy at Ho Chi Minh City · University Medical Center HCMC

   Affiliation as printed

   Department of Family Medicine, Faculty of Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam

   Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands

   Department of Respiratory Functional Exploration, University Medical Center, Ho Chi Minh City, Vietnam

2. Niels Henrik Chavannes Aachen Department of Public Health and Primary Care

   Leiden University Medical Center

   Affiliation as printed

   Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands